The present invention generally relates to combines and more particularly to an articulated (jointed) combine which employs, inter alia, an improved joint, unloading capability, grain transfer capability, airbag suspension, straw and chaff conveyor, suspended/movable fuel tank, control/steering, and extremely large grain storage capacity.
A modern agricultural combine typically unloads or transfers clean grain from its on-board storage hopper utilizing an auger of fixed length which swings out in a fixed radius and fixed elevation arc from its stowed position. The stowed position generally is pointing to the rear of the combine. The auger in turn generally is driven by a mechanical arrangement of belts, chains, clutch, and gearbox. The unload auger in most combine designs swings out to the operator""s left. The auger length generally is limited by the practical distance that it can extend beyond the rear of the combine in its stowed position without creating a serious maneuvering hazard.
As the size of on-board storage hoppers and capacity of combines has increased, the time required to maneuver the machine next to the grain receiving wagon or truck and the grain transfer time have become a major component of the total harvesting time. Conventional combines have a grain hopper capacity of 250 to 300 bushels and unload auger capacities of 1.9 to 2.6 bushels per second.
The unload time of the hopper typically is about 2 to 3 minutes with the unload auger running at maximum speed and 1 to 2 minutes are taken to maneuver the combine into the optimum unload position next to the truck or wagon. Re-positioning the combine and running the auger at less than maximum speed are often encountered when topping off the truck or wagon which is receiving the grain. As modern combine harvesting capacities approach 3,000 bushes per hour, the unload cycle must be repeated every 8 to 10 minutes. Therefore, the total unload time or non-harvesting time is a significant reduction of total grain harvesting productivity. A grain capacity of about 600-650 bushels would permit the combine to harvest for about 1 mile, which would greatly reduce unloading cycles.
This productivity loss can be countered by a second operator utilizing a tractor and grain cart following the combine back and forth through the field to unload the on-board combine storage hopper without stopping the harvesting process. Alternatively, a combine with an integrated grain cart, as disclosed in applicant""s U.S. Pat. No. 5,904,365 can be utilized to reduce the number of unload cycles and at least double the rate at which grain is discharged to the receiving vehicle.
Unloading combines into semi-trailer road trucks has become the prevalent practice as opposed to field wagons that were utilized in the past. These road trucks typically are parked at the side of the road and not in the field where the combine is operating. This necessary practice almost always creates an elevational difference between the two vehicles. These road trucks themselves also have widely varying heights. These two conditions create a big variation in the optimum elevation of the discharge point of the combine unloading system. Combine manufacturers have attempted to address this problem with ever-longer augers and higher fixed swing out arcs. There are, however, limits to both. This fixed point discharge point frequently ends up too high, too low, too far from the combine, or too close to the combine for optimum truck loading conditions. Such conditions require repositioning the combine with respect to the vehicle while it is unloading.
Existing combine unloading systems can unload from one side of the machine only. This frequently requires 180xc2x0 turns by the combine to position it on the proper side to unload the grain into the road truck. It also means that while harvesting the combine generally only can be unloaded into a moving grain cart only while traveling along the left-hand side of the unharvested crop since access to the unloader would be precluded by the unharvested crop were the combine to be located to the right of the crop.
When topping off or completely filling the truck or wagon, it is necessary for the operator to inch the combine forward or backward during the process. In addition to being cumbersome, the combine must be positioned close to perfectly parallel to the receiving vehicle or a stop and reposition is necessary. Moving the auger through its fixed arc frequently cannot solve the lack of parallel orientation.
An agricultural combine has multiple steering requirements. Precise control is needed as the row harvesting units such as a cornhead, are guided through the rows of grain. When the end of the field is reached, a tight turning radius is needed to proceed back across the field in order to harvest the crop immediately adjacent to the just-completed rows or round. Concomitant with its field performance, this large vehicle also must be controlled on the roadway at speeds of around 20 mph and around tight corners. Another steering associated problem is to turn multiple axle, heavily-loaded bogies with large tires in a tight radius while minimizing sliding the tires in the horizontal (particularly in the lateral) direction, which places high stresses in the suspension, piles up dirt in the field, and causes excessive tire wear.
Early attempts at an articulated combine are reported in U.S. Pats. Nos. 4,317,326 and 4,414,794. The design capacity is stated to be around 360 bushels. Its unloading mechanism is limited to one side of the combine and steering is accomplished only by articulation steering cylinders. U.S. Pat. No. 4,453,614 proposes a steering cylinder arrangement for an articulated combine. U.S. Pat. No. 4,204,386 proposes an articulated machine for gathering vegetables. U.S. Pat. No. 5,857,907 proposes a discharge conveyor having a secondary, variably extending conveyor attached to the terminal end of the discharge conveyor.
U.S. Pat. No. 6,012,272 (the ""272 patent) discloses an articulated combine composed of a forward unit or bogey having an operator""s cab, engine, grain harvesting assembly, grain transfer assembly, but no on-board grain storage; and a rear unit or bogey jointedly attached to the forward unit and having a steerable and powered wheel assembly, an on-board grain storage bin, and a grain off-loading assembly. Many of the industry long-felt, but unsolved needs regarding articulated combines are disclosed in the ""272 patent. Basic improvements thereto are the subject of this application.
One aspect of the present invention is a combine having increased on-board grain storage capacity. The combine includes a forward unit having an operator""s cab, an engine, a grain harvesting assembly, a grain transfer assembly, and is devoid of an on-board grain bin. The combine also has a rearward unit jointedly attached to the forward section. The rearward unit has a powered wheel assembly, an onboard grain bin for receiving grain from the forward section grain transfer assembly, and a grain off-loading assembly.
Another aspect of the present invention is directed to a joint for a powered articulated vehicle, such as a combine for joining a forward unit to a rearward unit. The joint includes an upper frame member carried by the forward unit and having a recess on its lower side and a lower frame member carried by the forward unit, having a recess on its upper side, and being spaced-apart vertically below the upper frame member so that the recesses are in vertical registration. The joint further includes a shaft carried by the rearward unit and a bearing retainer assembly carried by the end of the shaft and disposed between the recesses. The bearing assembly includes an outer annulus surmounting an inner hub which hub is connected to the shaft with thrust bearings inserted between the annulus and said hub, whereby the inner hub co-rotates with shaft with respect to the outer annulus. The bearing assembly also includes a pair of nibs carried by the outer annulus which nibs reside in the upper and lower recesses and which nibs are associated with tapered roller bearings so that the outer annulus co-twists with the shaft respect to the forward unit. Uniquely, the joint is stiff in the vertical plane through the longitudinal axis formed along the forward unit frame members and the rear unit shaft, i.e., around the pitch axis. It will be appreciated that the upper and lower frame members could be carried by the rearward unit and the shaft carried by the forward unit and the novel joint would function the same as with the configuration set forth above.
A further aspect of the present invention is an improved articulated combine comprising a forward unit connected by a joint to a rearward unit. The improvement for transferring clean grain from the forward unit to the rearward unit includes the rearward unit carrying an onboard grain bin and having a front wall that has a horizontal slot therein. The front wall retains a horizontally elongate grain transfer trough affixed thereto which trough is curved with its center of curvature congruent with the center of articulation of the combine. The trough is in communication with the bin via the slot. The forward unit carries a grain transfer assembly of a fixed elongate discharge chute that empties into the rearward unit trough while the forward and rearward units are being turned about the joint.
A still further aspect of the present invention is a grain unloading assembly for unloading clean grain from a combine grain bin, wherein a combine harvests grain and cleans it to provide the clean grain. Such grain unloading assembly includes a vertical flighted conveyor that is adapted to operate in either direction. Also included is a housing in which the vertical flighted conveyor is disposed. The housing is fitted at its top with a bin spout, a discharge spout, a moveable door that permits communication of the flighted conveyor either with the bin spout or with the discharge spout. A first opening at the bottom of the housing is covered with a moveable door for permitting grain in the bin to be moved into the housing for conveying by the flighted conveyor. A second opening at its bottom of the housing is for permitting clean grain to be passed into the housing from the combine.
Yet another aspect of the present invention is an unload assembly for unloading clean grain from a combine grain bin. This unload assembly includes a distal frame nested within a proximal frame. The distal frame is extensible from and retractable into the proximal frame. The distal frame has a discharge end for discharging grain. The proximal frame has a feed end for receiving grain from the grain bin and a distal end from which the nested distal frame extends and retracts. This unload assembly further includes a conveyor system that includes a first fixed pulley located at the feed end of the proximal frame. A second fixed pulley is located at the discharge end of the distal frame. A third fixed pulley is located at the distal end of the proximal frame. A fourth moveable pulley is disposed within the proximal frame intermediate the first and third fixed pulleys. The conveyor extends from the first pulley to the second pulley to the fourth pulley to the third pulley and back to the first pulley. A fifth pulley may be employed near the first pulley to increase the wrap angle of the conveyor belt around the first pulley. This arrangement permits the conveyor to extend as the distal conveyor extends and retracts as the distal conveyor retracts by movement of the fourth pulley.
Still a yet further aspect of the present invention is a straw and chaff spreader for mounting in association with a grain cleaner of a combine. This spreader includes a pair of generally horizontally-disposed, outwardly rotating, cleated conveyors disposed to receive straw and chaff discharged from the grain separator and cleaner of a combine.
A yet further aspect of the present invention is an airbag suspension for a vehicle having a vehicle frame having an axle (stub or through axle) extending therefrom. A longitudinal beam is affixed to the axle that carries at least one wheel. An airbag assembly includes an upper plate extending from the vehicle frame, a lower plate affixed to the longitudinal beam, and an airbag disposed between the upper and lower plates. The lower plate carries a pair of vertical blocks having vertical slots. A pair of cams is carried by the upper plate and rides in the vertical slots.
Another aspect of the present invention is a steering system for an articulated vehicle having a joint that connects a forward unit and a rearward unit and at least one articulation cylinder to provide a turning force at the joint. The steering system includes an operator speed and direction mechanism whereby an operator can direct the desired direction of the vehicle. A power source is provided for driving pumps adapted to drive motors and cylinders. The forward unit has tractive wheels (tired or tracked) powered by one or more motors. Each motor has a transducer for measuring its rotational speed and direction. The rearward unit has a pair of tractive endless tracks or tired wheels each powered by a separate motor. Each motor has a transducer for measuring its rotational speed. A programmable controller receives the rotational speed measurements (for over-speed control) and pressures from all of the transducers and operator steering commands from the speed and direction mechanism, and responds with suitable outputs. Actuators receive the controller outputs and adjust the output of each of the motors powering the rearward unit tracks/wheels.
A still further aspect of the present invention is an improved combine having a fuel tank, and which includes an overhead rail from which the fuel tank is suspended and an optional actuator connected to the fuel tank for moving the fuel tank forwardly and rearwardly. Desirably, though, the fuel tank can be moved forwardly and rearwardly by hand.
A still further aspect of the present invention is a method for articulating an articulated vehicle at a rest position wherein the vehicle is composed of a forward unit and a tracked rearward unit having a pair of powered tracks. The forward and rearward units are connected by a joint and an articulation cylinder. The method powers up only one track while simultaneously actuating the articulation cylinder.
Advantages of the present invention include a combine design, preferably an articulated combine, which enables grain storage capacity of between 500 and 1,000 bushels or more. Another advantage is an articulated combine which can unload clean grain to either side and which is controlled by a unique control system. A further advantage is a unique steering system for an articulated combine. These and other advantages will be readily apparent to those skilled in this art.